Chain-stitch shoe-sewing machine.



E. A. WEBSTER. CHAIN STITCH SHOE SEWING MACHINE.

APPLICATION IILBD JULY 23, 1910.

Patented Apr. 22, 1913.

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. E.'A. WEBSTER.

GH AIN STITCH SHOE SEWING MACHINE.

APPLICATION FILED JULY 23, 1910.,

Patented Apr. 22; 1913.

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, i a a ll/z ifiesss; jfweiz Z02 E. A. WEBSTER.

CHAIN STITCH SHOE SEWING MACHINE.

APPLICATION FILED JULY 23, 1910.

Patented Apr. 22, 1913.

3 SHEETS- SHEET 3.

' under a weak tension to the thread finger,

UNITED sTATns. PATENT curios EDWIN A. WEBSTER, OF GROVELAND, MASSACHUSETTS, ASSIGNOR TO HAVERHILL SHOE MACHINERY COMPANY, OF HAVERHILL, MASSACHUSETTS, A CORPORATION OF MAINE.

Specification of Letters Patent.

CHAIN-STITCH SHOE-SEWING- MACHINE.

Patent-ed Apr. 22, 1913,

Application filed July 23, 1910. Serial No. 573,424.

To all whom it may concern:

Be it known that I, EDWIN A. EBSTER, of Groveland, county of Essex, State of Massachusetts, have inventedflan Improvement in Chain- Stitch Shoe-Sewing Machines, of which the cation.

This invention relates to certain improve ments in chain-stitch, shoe-sewing machines, which are ordinarily-employed in Sowing the upper to the sole in turned and welted shoes, and more particularly to the type of machine shown and described in the patent to French 85 Meyer, #412,704, dated October 8, 1889. In the operation of this machine, the take-up o crates to set the stitch and to pull oil t read from the tension wheel as the needle is advanced through the work to loop-receiving position, the take-up being immediately lowered, giving oil thread to the auxiliary take-up, which suppliesthread loops-r and needle for the formation of the next stitch. With this timing, and operation .of the parts, while the stitch may be set with sufiicient tightness, particularly if a strong tension is employed, by the momentary pull placed on the thread by the-take-up, as it is lifted, and as it draws the thread from the thread wheel, yet I have discovered that this pull is exerted for such a short space of time that the leather will not yield to the thread suificiently, in the time afforded, to permit the stitch to be set as tightly as it might be with a lighter tension, under other conditions. In said prior machine, a thread finger is also employed which engages the thread between the looper and the needle and draws aside a certain amount of thread to be delivered to one leg of the needle loop, as the needle draws the loop through the work, but I have ascertained that,"while this device will operate in the desired manner when the machine is operated at a certain renders in the needle hook in one direction at the beginning of the return movement of the needle, and mustrender in the opposite direction during the latter portion of the following is a speoifiloop-drawing operation. I have further ascertained that the movement of the channel guide from the needle, which must occur while the needle is in the work, causes, in prior machines, a severe transverse strain on the needle, which frequently causes the same to become bent out of line and broken.

The objects of my invention are to pro vide a machine of the type above referredto, which is provided, essentially, with only the operating devices common to machines of said type, and in which sudden and undue variations in tension strain on the thread shall be prevented, threadbreakage will be reduced, and the shoe will constantly be held in position in the machine without material assistance by the operator, thereby enabling the shoe to be easily and accurately guided without special effiort on the part of the op erator.-

A further object of my invention is to provide a chain-stitch sewing machine of the above describedcharacter, in which means are provided whereby the stitches may be more tightly set with .a certain thread tension than they are with similar prior machines having the same thread tension; whereby rendering of the thread in the needle hook is prevented under all conditions of speed, and whereby transverse strain on the needle caused by the return movement of the channel guide is also prevented.

I accomplish these objects by maintaining ataut thread at all times during the formation of the stitch, so that the shoe is held in position by the thread when not held by the work engaging parts of the machine and the stitch, when set,will be firmly held until the leather yields under the maintained tension and then by tightening the thread under full tension again, so that the slack thread thus provided is taken up, and an extra stitch setting operation is performed; and further, by sotiming the loopcr with relation to the feeding movement of the channel guide that it acts, through the medium of the thread, to counteract fully the transverse strain thereon by the channel guide.

For a more complete understanding of my invention reference is made to the accompanylng drawings, in which I Figure l is a sldevelevation of. a shoe sewmg machine embodying my nvention. Figs. 2 to 7 inclusive are detail plan news, show? devices.

similar, in many respects, to the machlne inc; diil'erent positions of the stitclnforming mechanism Figs. 8, 9 and '10 are side elerations of the stitch formingand take-up mechanism, showing the parts indifferent positions. Fig. 11 is a similar view, of the stitch forming mechanism showing the parts in still another position. Fig, '12 1s a detail view of the take-up and thread tightening The machine illustrated in the drawing" disclosed in said prior patent of FIGIlCh-d'e Meyer 412,704 above referred to and, so far as the instrumentalities'thereof are con- 'cerned, no novelty is claimedithe refor, the

invent-ion residing principally in thetim'ing of these instrumentalities. For the purpose of identification, however, the various parts j will be briefly described.

indicates the curved,

to said segment, and a cam lever (1 oscillated .by a' suitable cam a on cam shaft 6, the 25 needle being arranged to move in a needle guide a.

.The looper c is rotatably mounted in a bearing 0, supported onthe frame of the machine, and is rotated to perform the loop;-

ing'oper'ation by means of *a rack bar 0?,

reciprocally mounted in guide ,ways 0 formed in the nose cysaid rack bar engaging a pinion c mounted-on the-end of, the loo-per, and being reciprocatedby means of a link 0 connected to a cam lever 0, (inarm of a cam lever cl, which is oscillated by a suitable cam on'the cam shaft. The channel guide. 6. is mounted on one arm a of a lever pivoted on a shaft 6 the opposite arm e of said lever having a cam roll 8' 'disposed to engage the surfaceof a cam e" on the cam shaft. Said shafts d and e are both mounted on a feed slide j, which ismounted toreciprocate Horizontally and longitudinally of the needle shaft, in the bracket 7 mounted on the frame of the ma chine, said bracket havinga longitudinal slot extending therethrough between the guideways' of the feed slide, and said feed slide having a rojecting portion f on which is mounted a guide way plate f, in which a slide f is mounted to reciprocate vertically, said slide f being connected to the middle portion of a T-shaped cam lever f, the T ends of which are mounted to oscillate in the bracket f" and in a bearing f on the frame of the machine, the opposite end of said lever f being engaged by a suitable I hooked needle carried on the needle segment a and oscillated on a shaft a by means of a link a connected- Siemens I .cam on the cam shaft 6. this means the {feed point and channel guide are moved in I the customary manner to feed the work.

. The take-up lever g is mounted to swing on a shaft g, and isprovided with a thread roll g in its extreme end, said lever g being oscillated bymeans of a link connected t-o'a cam lever 9 which is oscillated "by a suitable cam on the cam shaft. A thread'roll is also mounted on the-shaft g. A thread tightening arm h is. mounted to swing'on the shaft g and is provided with a thread roll 11. on its end beneath which the thread passes as it is carried from the roll g to the roll g A springh is connected to the arm hat one side' of its pivot and to the frame, and acts to throw said arm h downwardly,'and a stop-screw h .is provided on the frame for limiting the upward m oveme'nt of said arm; The thread :fin'g'er i mounted on a lever 71, pivoted at i on the frame, and oscillated by means of:-

a. link 71 connected at oneend to the upper end thereofand at-the other end to a'cam The. back gage 7', back rest m, and tension of wheel .n'are of. common fdrm,"-the' thread passing about said wheel a, tosecure the de sired friction engagementtherewith as it is drawn from the supply, and'passing over the roll g under roll h, over roll gand down {through the looper 'c', in the usual man ner. Assumingthat 'astitch has been taken, so that the thread. is fastened to the work, that the needle is holdinga loop of thread in its rear-most position,- the take-up g be.

ing in its lowest position, and the thread tightener h being heldby the thread against its stop,-as shown in Figs. 1 and 12 and thatth feedin motion has just taken place, so thdlfi the re ative position of the parts is that shownin Fi 2. The; operation from this point-.19 as ollows: 'As the. needle is advanced, the take-up is lifted correspondingly, and, as the needle enters the between su on theshank of the needle, and the take-up will draw thev loop tight about said shank andset the stitch, The thread tightener willat this time be drawn against itsstop' 71 and theiupward movement of the takeup is continued until it draws sufficient thread from the tension wheel n for the next stitch, preferably reaching its extreme elevated position by the time the needle reaches its exs treme forward position and )dwells to receive -the'loop. The ahoveigescribed operation is substantially as scribed in said French & Meyer patent. The thread' finger a, which, during this movement, has been held in its retracted position out of engagement with the thread, as shown in Fig. 3, is then advanced into engagement therewith,

stance, or work,- the loop will slipback drawing aloop thereof to one "side between and the point where it enters the locp'er, as

is drawn from two sources, firstfncm the stitch which has been set, by reason of further yielding of the leather between the time when the stitch was first set by the take-up, and the time when the thread finger is moved back' to draw aside the loop, and

second from the tension wheel. The takeup may be slightly lowered during this movement of the thread finger, so that some thread may also be supplied from this ,source, but, in order to perform the supplemental setting of the stitch inthe manner above described, the amount-of thread given elf by the take-up to the thread finger must be materially less than the amount of'thnead required for the loop which is drawn aside by the thread finger. It will therefore be i return movement of the channel understood that the reference to the dwell of the take-up, in the specification and claims is merely relative as to the movement of the thread linger, and to'be distinguished from a. timing in which the full supply of thread,

for the thread measuring movement of the thread finger, is derived either indirectly from an auxiliary take-up, after the main take-up has been lowered,-or directly from the take-up by the lowering thereof at a speed su-flicient to suppy thefull thread requirements of the thread finger.

During the forward movement 0fthe needle, the channel guide e willbe held as closely adjacent the path of the as practicable, as shown in Figs. 2, 3 and 4, the "do, away from the needle being accomplished while the needle is in work. According to my invention, after the supply of thread has been drawn aside by the thread finger, the looper, starting from the position of Fig. 4, is moved about the needle in the rear thereof to a positiondi rectly in front thereof, so that the thread isld rawn from the thread finger and laid a ainst the side of the needle next the channe guide, as shown in Fig. 5. At

' the same time the take-up is loweredsufiiciently to supply thread for this purpose,

, without decrease of the full tension which. is

placed on the thread by the thread tightener it. As soon as the thrbad-is laid a amst the shank of the needle, as shown in ig. 5, the return movement of the channel guide e is started, and is finished as the looper reaches 11 position in the rear of the needle, as shown in Fig. 6, tl1efeed point, at the same time, being thrown out of engagement with the workend also returned. As the channel guide is moved in the channel, during its return movement, and is at this timeonly work, the take-up as, durin'g'the return movement of the channel guide, the thread is drawn forcibly against the side ofthe needle next the chan-- nel guide from the opposite side thereof,un-

diet. the full, tension of'the thread t-ightener, during the entire eturn movement of the channel guide, it will be apparent that the thread is thus caused to resist the pull of tlm channel-guide'. on the needle. All transverse strain on the needle, either due to the relatively high tension atf which the thread is held during the looping operatiom'or to the pull on the work by theachannel guide, is

i practically avoided, as these strams are counterbalanced.

The-movement of the looper about the needle is continued until it assumes a position in front of the needle, as shown in Fig. 7., the talke up being lowered sulliciently to give off enough thread to permit the looper to finish its operation, and at the same time to maintain a taut thread under the full tenwithdrawn slightly from the channel, there sicn of the thread tightener. The needle isthen retracted to draw its loop toward the being lowered fast enough to supply'thread for this purpose.

The thread finger is heldsubstantially in its loop-holding position, of Figs. 4 to 7 and Figs. 9 and 10, until the thread which has been laid in the heck of the needle is actually drawn into contact with the work, as

shown in 'Fig. 10, and then it is moved back so that itbecomes disengaged from the thread, as shown in Fig. 11, so that, during the rest of the return movement of the needle, thread is suppliedto the opposite legs of the loop from the loop previously heldaside by the thread finger and from the further. lowering of the take-up, the

take-up reaching its lowest position just prevIo-us to the time when the needle reached its rearmost position, so that, when the thread is drawn intothe channel, itwill be tightened therein under the full tension'of the thread tightener. As the tension placed on the thread by the thread tightener, when held in, or adjacent its extreme position, is but slightly less than the 'full tension which is placed on the thread by the tension wheel, it follows that the stitch will be set practically as tight on the channel-side as on the needle side, thereby forming altighter stitch, with even less strain on the thread than would otherwise be required to set the stitch by depending solely on the action of the takeup in tightening the loop about the shank o 1ghe crlleledle. .h w v y e aying t e disenga i ,movement of the thread finger lint-i1 the%h rad is locked by the'wo'rk in theneedle hook, the thread tightener, which at all times places a strong tension on the thread, will not be permitted to draw back any of the thread held aside.

by the thread finger under any condition of speed, so that the constant maintenance of I the thread at a deg-ree of tautness notless than practically the full tension of the thread t ghtencr will not; interfere with the thread finger in the performance of' its normal or primary function. Inasmuch as the channel guide normallyextends to the bottom of the channel-and the thread is-notlocked by the work until the needle loop? has-been 'drawn into the between substance-beyond the bottom of the channel, it' follo ws that the thread finger does not release its 100p ing the greater portion of the sewing operation, the 'guiding'of the shoe is almost entirely automatic, thereby making the machine easy to operate and-enabling the prov duction of more uniform work; the holdting of the shoe in position during the return movement of the feeding devices being especially important in the accomplishment of this result. It may be observed in this connectionthat the function of the thread tightener is, merely to compensate for slight the tension claim as new anddesir'e to secure inaccuracies in the timing of the take-up cam and particularly for variations in the strength and' thickness of the stockfso; that the thread may beinaintained at ajngh Ade-'2 gree of taut'ness or at a all conditlons.

tension, strain under .Having described nay iriventiom-Y Patent is as follows I p ,7 Z: --Y 1 1. In a chain-stitch shoe-sewing inachmef, the combination of stitch forming' and stitch-setting, mechanism, including a tension-devi'cqa needle, a take-up and a thread finger, means to move the take-tip to draw thethread about'the shankof, the needle, while in the work, to pull off thread from device and tighten the i stitch under full tension strain, means to cause the take-up then to dwell, with tile thread held taut, and means to move the thread-finger. to draw aside a loop of thread adjacent the work under full tensionstrain, while. the

take-up thus dwells, thereby to take up slack thread due to the yielding of the work to the thread and further tighten the stitch, substantially as described.

2. In'a chain-stitch shoe-sewinglmachine,

' the combination of an oscillatory, hookedneedle, a thread-finger, a thread-supply, means includinga take-up, to set the stitch by drawing the thread about the shank of the needle, while in the work. under a stitch-setting strain, means to more the thread-finger away from the needle to measure off a loop of thread foron'e side of the thread under a stitch settingstrain from the xtimt of the stitclrsetting operation by'the take-up, until after the time of the threadmeasurilig operation of the thread-finger, -'and means thereafter to operate the threadfinger-to retain its loop, while the thread 'is "still held taut by the thread tightener and without giving up thread thereto through the needle hook, until the needle loop is held from movement in the needle hook by the work, substantially as described.

3. In a chain-stitch shoe-sewing machine I f 'the combination of sti ch-forming and stitch-setting mechanism including a tension-' device, a needle,'a take-up, a thread-finger and a"spring-actuated thread-tightener, ar-' ranged, whenmoved to its extreme position, to please stitch-setting strain on the thread of a somewhat less degree than the full tension, means tomove the take-up to draw the thread about the shank of the needle while in the work, to pull off thread from the tensiondevice and tighten the stitch under full ten sion strain, and to cause the-take-up then to dwell with the thread'held taut, means to move the thread-finger away fromthe needle to deflect the taut thread adjacent the work under stitch-setting strain, while the take'-' up thus dwells, and means thereafter to op crate the thread-finger to retain its loop, "while the thread is still heldtaut by the thread-'tightener, and without giving up fthread thereto through the needle hook, until-the needle loop is held from movement Y i in the needle hook by the work, substan- Y tially as described.

4. In a chain-stitch shoe-sewing machine I the combination of-an oscillatory, hooked needle, a looper, a work-feeding-device, a

"thread-tension, means to move said workfeeding-device toward the path of the needle todeedthe work while the'needle is-withdrawn therefrom, means to advance the needle through the work to loop-receiving position, means to move the looper' to lay the thread against the side of the needle next to said feeding device, thread taut, between the tension and the work, during the looping operation, therebycausing a transverse pressure on the needle in one direction, and'means tomove said feeding device away from the needle in contact with the work, so as to produce a drag thereon in the opposite direction, while the needle is thus pressed, whereby the transverse strain on the needle by the action of the feeding device on the Work is counteracted, substantially as described.

5. A chain-stitch shoe-sewing machine.

means to hold the a Games at this patient may beobtained for five cents eachQby addressing the Commissioner of Qatents,

" nel-guide toward the path of, the needle during the feeding operation and while the needie is Withdrawn from the Work, meansto advance the needle through the Work to loop-receiving position, means to move the looper from a position in the rear of the needle to a position in front thereof, to lay the thread, as it is drawn from the work, against the side of the needle next. the channel-guide, and, thereafter, simultaneously to move the looper, eration, and to move the channel-guide away from the needle, While said channel guide to complete its 1o0ping.op-.

is in engagement with the Work, to perform its return movement, and means to hold the thread taut during said looping operation, whereby the transverse strain placed on the needle by the Work, through the drag of the channel-guide thereon during its return movemen'tfis oounteracted substantially as. described.

In testnnonywvhereof, 1 have signed my nameto this specification, in. the presence of two subscribing witnesses.

EDWIN A; WEBSTER.

Nitnesesr L. H. maintain, H. B. Davis.

Washington, D. G. v 

